有一串数:5,55,555…{555…5(15个5)}这一串数的和的末三位数字是几?6b.R1T(?6I2['X(V;m;O
算式:提示;]2G0v8a4~3k7J,K-^6b.R1T(?6I2['X(V;m;O
答:这一串数的和的末三位数是'R*r)S2]。6b.R1T(?6I2['X(V;m;O